Internal gauge for bores



Nov. 2s, 1944. W QARDWARE 2,363,587

INTERNAL GAUGE FOR BORES NOV. 28, 1944. W HARDWARE4 363,587

INTERNAL GAUGE FOR BORES Filed Aug. 5, 1945 5 Sheets-Sheet 2 25 -J lzvvezzfoz Nov. 28, 1944. w. HARDWARE 2,363,587

INTERNAL GAUGE FOR BORES Filed Aug. 5, 1943 K 3 Sheets-Sheet I5 L l .in u 18 32 Figi 6.

t Patented Nov. 28, 19.44

UNITED l STAT .lINTERNAL GAUGE FoavoREs r WalterHardwa're, Peterboough,` England Application August 3, 1943, `Serial No'.y 497,233* i `In Great Britain August 4,1942

` iclaims; (c1. '33;178)

1 .'Ifhis invention relates tointernal gauges for gaugingor measuring thediameter of parallel or. tapered `bores orother bores, particularly long bores such as for recoil or recuperator cylinders orbores for guns or for gun or like barrels, the invention being especially usefulfor gaugingor gauge checking ,during machining operations. W,An-object of the present inventio-naistoprovide a device for accurately gauging bores at anylongitudinal .position .within thebore, the dimensions oiothegbore `being determined progressively or otherwise at selected longitudinal distancesvandlread externally of the bore `by laid of calibrations indicating radial` or vdiametric .measurements and the longitudinal position of such measurements t `This invention consists in` an `internal ,gauge for bores comp-rising a tribe, a spindlelno-unted Within the tubeandcoaxial therewith, said tube and spindle .being capableof relative rotary move.

" ment, a gaugingl head mounted uponthe tube at I one end thereof, said head `having three` spaced plainradial holes, feeler pinsfmounted in said. holes, one of said pins being radially adjustable for.gauging,purposes, the other pin being fixed relatively to said adjustable pin, `a pin operating;

o elementimounted onthe spindle to be rotatable therewith, said element comprising a snailcam engagingthe adjustable feeler pin,` and allaterally adjacent .cylindrical `portion engagingythe:

relatively xed pins. I z

u In the accompanying drawings: I Figure 1 is alongitudinal section ofthe improvedgauge; Y* o I "Eigure 2 is an outside View; o o Figure 3ds anend View on an enlarged scale; Figures land 5 are detail views of aca-m;

4ligures 6 and. 7 are details of a-modied arrangement;ofvmanipulating head;

Figures 8V and 9 are details ofi-a manipulatin neadincorporating areturningspring. i

. j VIn.carrying theinvention into effect `acf'zording to ne convenient mode as` applied by Way of `exampletda gauge device Vfor. gauging a recuperator.bore` a tube"V I .of appropriate length has mounted at one end a plug or bushing 2 through which a bore is provided rotatably to accommo` datewanoperanng `md 0.1 spindle `aeescrited be- 1oW.` f The other `end ofthe rod has a gauging head 4.` `ooznprising a cylindrical or housing element 5 provided with a` rearwardly extending sleeve or bushing 6 inwhich therod 3,is rotatably mounted but which is capable `ofA a limited axial displacement therein for adjustment pfurposes.v The forward-rend. otvthefhead is provided with a `cavityr'l `adapted to` receive a pinoperatingring or disc 8 or like element` carrying cam means.`

This element 8- is xedonthe end of the rod 3. In the wall ofthe, head 4` surroundingthe operating element 8 three radial bores I9 `are provided atv .126 16o-r other -suitable angle) to one another for thereception of feeler` pinsllla, Ib; IIlc,`I the bores affordinga sliding t, for the pins to enable them to be displaced radiallywinfthe. head `When l taking af gauge` reading.; TheL pins Illa,` 1012,. Ic are' prevented from rotationabout theiroownaxes land are under` the influence of springs I Igadapted to tend to thrust them in wardgly towards the axis I of thef tube. For.` example,lthe.outerside wall of eachfbore `9 may have a radial slot 30 through which ayguide pin `I2 xed in the side `of each feeler pin 10a, Ib," I Dc: is *adapted` toslide and which serves as a connection for oneend' of `a tension spring II located radially `of the head. and which `is attachedto' a` ringt29` or other anchorage `adjacent the centre' oftheelement, I w i Y i if y Upon the outer surface .0f the tube I a locat-` ing `guide ring I4 is provided comprising a sleeve I5 within which the tube is slidable and an outer periphery I6 of Trusto-conical or tapered form` so that it may be tted into the end of the bore the depth or longitudinal' position of the gauging head 4 `determinedbypreference to calibrations" marked longitudinally on the outside of the tube;` Coaxially of the tube I, `the spindle or rod3 referred toabove `islocat'ed, the outer e'ndrof which passes through` the plug 2 in the outer end ofthe tube and `terminates in a taper I 'Ian'd screw `thread I8., .A manipulatingring ISis tight` ly` fitted on `the taper i portion: Il andfsecured by* means of a lock nut 20, the taper formationen` abling the manipulating rin-g I9 `to be initially adjustable angularly with respect to therod 3. The outer surfacexof the ring I9 isconveniently milled -for manipulatingfpurposes and calibrations 2I are. provided upon iter upon the adjacent end plug of the tubevanda zero or datum mark 22 is provided uponthe one orthe othenx .Therinner end of the rod 3 is rotatablymounted within the sleevey of the head 4 and: secured longitudinally. .by a. i grub screw 23 engaging With t a groove 2'4" in the'` outer surface of the rod 3. The operatingring or element 8 has a plain cylin.l drical portion" 25noaxia1` with `the `rod 3` and lonf either sideuofthis cylindrical portion `a cam z26? r is ,l positioned` flangewisa. .the cams I being offf thec snail type extending over 360, that is to say, each cam has a continuous curve which commences at zero at the same or substantially .the same radius as the plain cylindrical part 25 while the maximum throw at the terminal step of the cam is located adjacent and upon the other side of the zero position. v

Of the three feeler pins that are located in the bores in thegauging head 4, two Illa,|0b are provided with inner reduced ends 2'I adapted to ride upon the plain cylindrical portion 25 and are' held against this portion by the springs Il, while the third pin ,Ic bridges the plain portion 25 and rides upon the cam anges l26.' The outer or sensitive end` 28 of each pin is a partoi` a sphere or is conical and the adjustment of the cam-controlled pin IDC displacesthe head 4 V lslightly and centres the ends of the three pins.A

It will k=be appreciated that by rotating the caliing spring 38 the ends of which are secured respectively to the ring I9 by a pin 394and tothe bushing 2 by a split pin 40.

By the provision of the returning spring 38, after taking a reading and releasing the manipulating ring I9, the ring automatically returns to the Zero position so that the feeler pin is re" tracted thus avoiding damage to the pin or to the bore Ibeing. gauged, suchen mightjoccur where an operator forgets to .turnnthefmanipulating ring in the reversedirection. Stop pins 4I, 42

carried by the bushing 2 and manipulating ring limit the return or zeroising movement. The

iiange of the bushing 2 may be provided with an adjustablezero band 43 for adjusting the` zero f mark as in the case of the disc 33 (Figure 6). Iclaim: l I Y 41`. An 'internal gauge for bores, comprising. a tube, a spindle mounted within the tube and coaxial therewith, said tube and spindle being capable ofl relative rotary movement, a gauging head mounted uponthe tube at one end thereof, said head havingv three spaced plainradial ulating ring I9 is reversed this pn'will be retracted by its spring I I. Theother two pins Illa, Ib are not directly affected by the rotation'of the cams. I

In operation, assuming the locating vand guide ringI I4 to be positioned within the bore mouth, the'gauging head 4 may be slid longitudinally withinthe ybore to the desired depth,fwhich may be gauged against the' longitudinal calibrations `Iii `on the outer side ofthe tube I.` The diameter gauged atthis lsetting may then `.be read 'by rotating the manipulating ring I9 causingthe dis` The thrust of placement of the cam pin I0c. 'the cam pin against the wall of the bore will cause the other two pins Illa, Ib to engage the wall of the bore and the three pins will accommodate themselves to the circumference of the bore, and the diameter is read oif on the calibrations, at the manipulating ring I9. When it is desired to gauge the diameter at another longitu-V dinal position the manipulating ring I9 is reangularly adjustable manner by means of screws 32 in arcuate slots, a zero disc 33. The zero disc carries a zero or datum mark 34 against which `calibrations on the. manipulating head I9 are4 read. fShould wear or other conditions arise the zero disc 33 can be slackened from the tube ange 3l andthe zero mark 34fbrought again into register with the zero `mark on the manipulating head I9 after which the zerodiscisv again locked to the ange 3| by the screws 32.'

Referring to Figures 8 and 9, the rod 3` may be mounted in anti-friction bearings such as needle bearings 35 located at spaced points in the'tube I and bushing 2.` Thebearings in the tube I may lbe supported by screws36. gauging head 4 may also have needle'bearings or ball bearing" support; The manipulating ring I9 is recessed at 3'!v toaccommodate a spiral return- The` . gaging the adjustable feeler pin and a cylindri' holes, feeler pins `mounted in said holes, one of, said `pins being radially adjustable for gauging purposes, the other pins being xedrelatively to said -adjustable pin, al pin operating element mounted'on the spindle to bev rotatable therewith, said element comprising a snail cam engaging the adjustable feeler pin, and a laterally' adjacent cylindrical portion engaging the relatively xed pins.

2; An internal gauge for bores, comprising a tubea. spindle-mounted within the tubeand coaxial therewith, said tube and spindle being capable of relative lrotary movement, a housing mounted upon the tube at one end thereof, said housing having threespaced plain radial holes, feeler pins mounted in said holes, oneof said pins being `radially adjustable for gauging purposes', the other pins being fixed relatively to the adjustable pin, a pin operating elementvmounted on thespindleto be rotatable therewith, said element being located within the housing and comprising ai pair of axially spaced snail cams encal portion located between the cams and en gaging'the relatively fixed pins. 3. An internal gauge for boresy as claimedintv claimy 2, wherein the cams extend over 360.

4. An internal gauge for bores as claimedin claim 2, wherein spring means are provided for holding the pins on the cams and said cylindrical portion, said spring means -comprising a plural-L ity of coiled springs connected by oneof the ends to the pins, the other ends being connected tor a common ring. v

5L Anfinternal gauge for bores, as claimed in claim 2, wherein the tube' is provided with longitudinally extending depth calibrations. 6. Aninternal Vgauge for bores as claimed in claim '2, -Wherein the spindlev at its outer end is provided with a manipulating knob calibrated forl rotary movement and the tube is provided'lwith an'an'gularly adjustable Zero ring adjacent saidV 7. A internal gauge for bores as .claimedl in claim 2,-'wherein the spindle at its outer end is provided with a manipulating knob calibrated for rotary movement, a returning springbetween the knob andthe tube stressed by a calibrating movement of the knob, said spring returning theparts to zero when the knob released.

WALTER HARDWARE. 

